1. Field of the Invention
The present invention relates to a heat sink for cooling various heat generating electronic components, particularly, a semiconductor device and the like, and a cooling method.
2. Description of Related Art
When electronic components such as a semiconductor device, which are mounted on various devices including personal computers and the like or on electrical or electronic installations including electronic equipment and the like are used, they inevitably generate heat to some extent. Cooling of such generated heat is becoming a serious technical problem in recent years. Typically known as methods for cooling electrical or electronic devices which require cooling, are a method of lowering air temperature inside the housing of the device by a fan mounted on the device, a method of cooling a heat generating device, for example, a heat generating electronic component by attaching a cooling body on the heat generating device, or the like to cool same, and the like.
Such cooling bodies as mentioned above include a heat conductive metal member such as metal plate or metal block. For example, heat generated by a heat generating device is received by a metal block and then, the heat is dissipated by means of a heat dissipating fin mounted on the metal block. To have a limited envelop volume which is light weighted but has a wider heat dissipating area, (mountain-shaped) corrugated fins, caulked fins or the like are effective and widely used. In order to improve the heat conductivity, a heat transfer rubber sheet or the like is used between the heat generating device and the metal member. Further, as a method for fixing heat dissipating fins on the aforementioned metal block, there are used methods of brazing, soldering, caulking, adhering by use of an adhesive agent or a double-sided adhesive tape, screwing or the like.
According to the aforementioned method in which heat from the heat generating device is first received by a heat transfer metal block or the like and then, dissipated to a predetermined area or an open air by way of heat dissipating fins fixed on the metal block or the like, a metal plate, metal block or the like is placed at a heat path between a heat generating device, which is a heat source, and the heat dissipating fins, and then, there is contact heat resistance produced between the metal plate, metal block or the like and the heat dissipating fins, which presents a problem that heat dissipating performance is deteriorated over the whole heat sink.
In addition, there is another problem that cost is increased due to the need to prepare a member other than the heat dissipating fins and joint it with the heat dissipating fins. Further, when the member other than the heat dissipating fins and the heat dissipating fins are jointed to another member, there is also produced contact resistance. This presents a problem that contact resistance values vary dependent on the products. Furthermore, there is still another problem that a heat sink causes unnecessary radiation, which lowers heat cooling efficiency.
Accordingly, an object of the present invention is to solve the aforementioned conventional problems and to provide a heat sink for cooling electronic devices or the like, which has a reduced contact heat resistance between a metal block and heat dissipating fins, uniform cooling performance irrespective of products, reduced unnecessary radiation and excellent cooling performance, and a heat dissipating method.